This invention relates to an electronic monitoring device and more particularly to a visual indicator of tempo accuracy. The present invention enables a musician, a sound technician, or engineer to visually determine whether a percussive transient sound being monitored occurs at the same time as a reference signal; and, if it does not occur at the "correct" time, the device visually indicates the magnitude of the temporal inaccuracy.
Music that sounds "tight" and not sloppy happens only when certain notes from different instruments occur together, at nearly the same instant. For example: a bass drum beat and a bass guitar note, a snare drum beat and a tambourine hit, a metronome beat and a bass drum, a rimshot and a rhythm guitar "chink", a cymbal crash and a bass drum beat, a keyboard stab and a snare drum. The present invention compares the timing of any two events, revealing which is ahead or behind and by how much.
There have been numerous devices noted in the prior art which are intended to provide musicians with comparisons of a measured reference parameter to that of an inputted parameter. U.S. Pat. No. 3,905,269 discloses an electronic rhythm teaching mechanism. The musical student inputs the correct timing parameter so that a metronome will click at the correct frequency. The device provides a light display portion which receives a card having musical notes inscribed upon it. The musical notes inscribed on this card represent the musical passage or exercise to which the student is to be tested. Upon reception of the first note played by the musical student, the electronic rhythm teaching machine will begin the judging process of comparing the playing of the monitored note and the referenced note for the remaining notes contained in the musical passage or exercise. If the musical student plays the subsequent note at the correct time, with the correct rhythm, this note is illuminated by the electronic rhythm teaching machine to inform the music student that the rhythm being played is correct. Should the musical student play the note at the wrong time, the electronic rhythm teaching machine will not illuminate the reference note, thereby informing the musical student that the presently played musical rhythm is incorrect.
Thus, the device of U.S. Pat. No. 3,905,269, essentially indicates whether the student has "passed or failed" in playing the musical selection. There is no visual display of the actual time difference of arrival between the compared rhythms, and there is no teaching of which rhythm input is first received by the measuring apparatus.
U.S. Pat. No. 3,919,915 discloses an electronic music conductor for generating a recording signal of different frequencies corresponding to the different beats in the meter of musical material simultaneously with the recording of the musical material.
Upon playing back the recorded signals, these signals are detected according to their frequencies and are utilized to illuminate lamps corresponding to the detected frequency. Illumination of lamps informs a performer, who is performing a live performance in conjunction with pre-recorded instrumental background music, the correct rhythm to be used in order to perfect the synchronism of the live performance with the playback of the recorded musical material.
U.S. Pat. No. 3,919,915 does not disclose nor teach the detection of two separate rhythms with a comparison step in order to determine whether the rhythms are in synchronism, but merely teaches the method and device for indicating to a performer the correct rhythm to be used during a performance.
An instrument tuner capable of electronically generating a visual display of a frequency difference between two frequencies is disclosed in U.S. Pat. No. 4,078,469. While the disclosed device teaches that the actual difference between a sustained reference frequency and a sustained inputted frequency can be visually displayed to the operator so that the operator can readily adjust the instrument to obtain a perfected pitch, the disclosure does not teach the measurement, detection, and comparison of the temporal relationship between a test, percussive transient input and reference percussive transient input as shown in the present invention.
Another electronic pitch tuner is disclosed in U.S. Pat. No. 4,120,229, wherein the device compares the frequency of an inputted musical sound signal from a microphone which is produced by a musical instrument to be tested with the frequency of a reference oscillator. The tuner utilizes a phase comparison between the reference frequency and the tested frequency to determine whether the frequencies are in synchronism with each other. Based upon this phase comparison, the electronic tuner visually indicates to the operator the status of the synchronism between the reference frequency and the frequency to be tested. More specifically, the electronic tuner indicates the difference in the pitch between the reference source and the instrument being tested. Again, the disclosure of U.S. Pat. No. 4,120,229 does not teach or disclose which signal is first received by the measuring apparatus, nor does it teach or disclose any visual display of an actual time difference between compared percussive transient signals.
An automatic performance device capable of adjusting the progress of an automatic performance in response to the depression of keys by a performer is disclosed in U.S. Pat. No. 4,484,507. This automatic performance device allows a performer and an automated performance to maintain the same tempo and rhythm throughout the performance. To achieve this result, the automatic performance device monitors the tempo and rhythm of the performer and compares this tempo and rhythm with the tempo and rhythm of the automatic performer. If the automatic performance device detects a difference between the measured tempo and rhythm and the automated tempo and rhythm, the automatic performance device will adjust its automated tempo and rhythm with respect to this difference so that the next note played by the performer should have the correct tempo and rhythm as that of the automatic performer. Thus, if the performer is depressing the keys in a fashion that is faster than the progress of the automatic performance, the automatic performance device will increase its tempo in order to overcome the time discrepancy between the manual and automatic performance. This is also the case if the manual performance is lagging behind the automatic performance. U.S. Pat. No. 4,484,507 does not disclose a display means for informing the performer of the discrepancies between the tempo of the performer and the tempo of the automatic performance.
Other prior art which discloses technical background of various electronic metronomes and tone teaching devices may be noted in U.S. Pat. Nos. 4,630,518; 4,089,246; 4,090,355; 4,437,381; and 4,024,789.
While the prior art may teach the concept of measuring a particular musical parameter, comparing this measured parameter with a reference parameter, and displaying to an operator the difference generated in the comparison step, such prior art lacks a distinct teaching on the arrival time between compared percussive transient signals and then visually representing any temporal disparity.